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Why Specified Complexity Cannot Be Purchased without Intelligence

By William A. Dembski

(Used By Permission)


How a designer gets from thought to thing is, at least in broad strokes, straightforward:

(1) A designer conceives a purpose.

(2) To accomplish that purpose, the designer forms a plan.

(3) To execute the plan, the designer specifies building materials and assembly instructions.

(4) Finally, the designer or some surrogate applies the assembly instructions to the building materials.

What emerges is a designed object, and the designer is successful to the degree that the object fulfills the designer's purpose. In the case of human designers, this four-part design process is uncontroversial. Baking a cake, driving a car, embezzling funds, and building a supercomputer each presuppose it. Not only do we repeatedly engage in this four-part design process, but we've witnessed other people engage in it countless times. Given a sufficiently detailed causal history, we are able to track this process from start to finish.

But suppose a detailed causal history is lacking and we are not able to track the design process. Suppose instead that all we have is an object, and we must decide whether it emerged from such a design process. In that case how do we decide whether the object is in fact designed? If the object in question is sufficiently like other objects that we know were designed, then there may be no difficulty inferring design. For instance, if we find a scrap of paper with writing on it, we infer a human author even if we know nothing about the paper's causal history. We are all familiar with humans writing on scraps of paper, and there is no reason to suppose that this scrap of paper requires a different type of causal story.

Nevertheless, when it comes to living things, the biological community holds that a very different type of causal story is required. To be sure, the biological community admits that biological systems appear to be designed. For instance, Richard Dawkins writes, "Biology is the study of complicated things that give the appearance of having been designed for a purpose."(1) Likewise, Francis Crick writes, "Biologists must constantly keep in mind that what they see was not designed, but rather evolved."(2) Or consider the title of Renato Dulbecco's biology text -- The Design of Life.(3) The term "design" is everywhere in the biological literature. Even so, its use is carefully regulated. According to the biological community the appearance of design in biology is misleading. This is not to deny that biology is filled with marvelous contrivances. Biologists readily admit as much. Yet as far as the biological community is concerned, living things are not the result of the four-part design process described above.

But how does the biological community know that living things are only apparently and not actually designed? According to Francisco Ayala, Charles Darwin provided the answer: "The functional design of organisms and their features would therefore seem to argue for the existence of a designer. It was Darwin's greatest accomplishment to show that the directive organization of living beings can be explained as the result of a natural process, natural selection, without any need to resort to a Creator or other external agent. The origin and adaptation of organisms in their profusion and wondrous variations were thus brought into the realm of science."(4) Is it really the case, however, that the directive organization of living beings can be explained without recourse to a designer? And would employing a designer in biological explanations necessarily take us out of the realm of science? The purpose of this book is to answer these two questions.

The title of this book, No Free Lunch, refers to a collection of mathematical theorems proved in the last five years about evolutionary algorithms. The upshot of these theorems is that evolutionary algorithms, far from being universal problem solvers, are in fact quite limited problem solvers that depend crucially on additional information not inherent in the algorithms before they are able to solve any interesting problems. This additional information needs to be carefully specified and fine-tuned, and such specification and fine-tuning is always thoroughly teleological. Consequently, evolutionary algorithms are incapable of providing a computational justification for the Darwinian mechanism of natural selection and random variation as the primary creative force in biology. The subtitle, Why Specified Complexity Cannot Be Purchased Without Intelligence, refers to that form of information, known as specified complexity or complex specified information, that is increasingly coming to be regarded as a reliable empirical marker of purpose, intelligence, and design.

What is specified complexity? An object, event, or structure exhibits specified complexity if it is both complex (i.e., one of many live possibilities) and specified (i.e., displays an independently given pattern). A long sequence of randomly strewn scrabble pieces is complex without being specified. A short sequence spelling the word "the" is specified without being complex. A sequence corresponding to a Shakespearean sonnet is both complex and specified. In The Design Inference(5) I argued that specified complexity is a reliable empirical marker of intelligence. Nevertheless, critics of my argument have claimed that evolutionary algorithms, and the Darwinian mechanism in particular, can deliver specified complexity apart from intelligence.(6) I anticipated this criticism in The Design Inference but did not address it there in detail. Filling in the details is the task of the present volume.

The Design Inference laid the groundwork. This book demonstrates the inadequacy of the Darwinian mechanism to generate specified complexity. Darwinists themselves have made possible such a refutation. By assimilating the Darwinian mechanism to evolutionary algorithms, they have invited a mathematical assessment of the power of the Darwinian mechanism to generate life's diversity. Such an assessment, begun with the No Free Lunch theorems of David Wolpert and William Macready (see section 4.6), will in this book be taken to its logical conclusion. The conclusion is that Darwinian mechanisms of any kind, whether in nature or in silico, are in principle incapable of generating specified complexity. Coupled with the growing evidence in cosmology and biology that nature is chock-full of specified complexity (cf. the fine-tuning of cosmological constants and the irreducible complexity of biochemical systems), this conclusion implies that naturalistic explanations are incomplete and that design constitutes a legitimate and fundamental mode of scientific explanation.

In arguing that naturalistic explanations are incomplete or equivalently that natural causes cannot account for all the features of the natural world, I am placing natural causes in contradistinction to intelligent causes. The scientific community has itself drawn this distinction in its use of these twin categories of causation. Thus, in the quote earlier by Francisco Ayala, "Darwin's greatest accomplishment [was] to show that the directive organization of living beings can be explained as the result of a natural process, natural selection, without any need to resort to a Creator or other external agent."(7) Natural causes, as the scientific community understands them, are causes that operate according to deterministic and non-deterministic laws and that can be characterized in terms of chance, necessity, or their combination (cf. Jacques Monod's Chance and Necessity).(8) To be sure, if one is more liberal about what one means by natural causes, and includes among natural causes telic processes that are not reducible to chance and necessity (like the ancient Stoics did by endowing nature with immanent teleology), then my claim that natural causes are incomplete dissolves. But that is not how the scientific community by and large understands natural causes.

The distinction between natural and intelligent causes now raises an interesting question when it comes to embodied intelligences like ourselves, who are at once physical systems and intelligent agents: Are embodied intelligences natural causes? Even if the actions of an embodied intelligence proceed solely by natural causes, being determined entirely by the constitution and dynamics of the physical system that embodies it, that does not mean the origin of that system can be explained by reference solely to natural causes. Such systems could exhibit derived intentionality in which the underlying source of intentionality is irreducible to natural causes (cf. a digital computer). I shall argue that intelligent agency, even when conditioned by a physical system that embodies it, cannot be reduced to natural causes without remainder. Moreover, I shall argue that specified complexity is precisely the remainder that remains unaccounted for. Indeed, I shall argue that the defining feature of intelligent causes is their ability to create novel information, and in particular specified complexity.

Design has had a turbulent intellectual history. The chief difficulty with design to date has consisted in discovering a conceptually powerful formulation of it that will fruitfully advance science. While I fully grant that the history of design arguments warrants misgivings, they do not apply to the present project. The theory of design I envision is not an atavistic return to the design arguments of William Paley and the Bridgewater Treatises. William Paley was in no position to formulate the conceptual framework for design that I shall be developing in this book. This new framework depends on advances in probability theory, computer science, the concept of information, molecular biology, and the philosophy of science -- to name but a few. Within this framework design promises to become an effective conceptual tool for investigating and understanding the world.

Increased philosophical and scientific sophistication, however, is not alone in separating my approach to design from Paley's. Paley's approach was closely linked to his prior religious and metaphysical commitments. Mine is not. Paley's designer was nothing short of the triune God of Christianity, a transcendent, personal, moral being with all the perfections commonly attributed to this God. On the other hand, the designer that emerges from a theory of intelligent design is an intelligence capable of originating the complexity and specificity that we find throughout the cosmos and especially in biological systems. Persons with theological commitments can co-opt this designer and identify this designer with the object of their worship. But this move is strictly optional as far as the actual science of intelligent design is concerned.

The crucial question for science is whether design helps us understand the world, and especially the biological world, better than we do now when we systematically eschew teleological notions from our scientific theorizing. Thus a scientist may view design and its appeal to a designer as simply a fruitful device for understanding the world, not attaching any significance to questions like whether a theory of design is in some ultimate sense true or whether the designer actually exists. Philosophers of science would call this a constructive empiricist approach to design. Scientists in the business of manufacturing theoretical entities like quarks, strings, and cold dark matter could therefore view the designer as just one more theoretical entity to be added to the list. I follow here Ludwig Wittgenstein, who wrote: "What a Copernicus or a Darwin really achieved was not the discovery of a true theory but of a fertile new point of view."(9) If design cannot be made into a fertile new point of view that inspires exciting new areas of scientific investigation, then it deserves to wither and die. Yet before that happens, it deserves a fair chance to succeed.

One of my main motivations in writing this book is to free science from arbitrary constraints that, in my view, stifle inquiry, undermine education, turn scientists into a secular priesthood, and in the end prevent intelligent design from receiving a fair hearing. The subtitle of Richard Dawkins's The Blind Watchmaker reads Why the Evidence of Evolution Reveals a Universe Without Design. Dawkins may be right that design is absent from the universe. But science needs to address not only the evidence that reveals the universe to be without design but also the evidence that reveals the universe to be with design. Evidence is a two-edged sword: Claims capable of being refuted by evidence are also capable of being supported by evidence. Even if design ends up being rejected as an unfruitful explanatory tool for science, such a negative outcome for design needs to result from the evidence for and against design being fairly considered. Darwin himself would have agreed: "A fair result can be obtained only by fully stating and balancing the facts and arguments on both sides of each question."(10) Consequently, any rejection of design must not result from imposing arbitrary constraints on science that rule out design prior to any consideration of evidence.

Two main such constraints have historically been used to keep design outside the natural sciences: methodological naturalism and dysteleology. According to methodological naturalism, in explaining any natural phenomenon the natural sciences are properly permitted to invoke only natural causes to the exclusion of intelligent causes. On the other hand, dysteleology refers to inferior design -- typically design that is either evil or incompetent. Dysteleology rules out design from the natural sciences on account of the inferior design that nature is said to exhibit. In this book I shall address methodological naturalism. Methodological naturalism is a regulative principle that purports to keep science on the straight and narrow by limiting science to natural causes. I intend to show that it does nothing of the sort but instead constitutes a straitjacket that actively impedes the progress of science.

On the other hand, I shall not have anything to say about dysteleology. Dysteleology might present a problem if all design in nature were wicked or incompetent and never matched up with our moral and aesthetic yardsticks. But that's not the case. To be sure, there are microbes that seem designed to do a number on the mammalian nervous system and biological structures that look cobbled together by a long trial-and-error evolutionary process. But there are also biological examples of nano-engineering that surpass anything human engineers have concocted or entertain hopes of concocting. Dysteleology is primarily a theological problem.(11) To exclude design from biology simply because not all examples of biological design live up to our expectations of what a designer should or should not have done is an evasion. The problem of design in biology is real and pervasive, and needs to be addressed head on and not sidestepped because our presuppositions about design happen to rule out imperfect design. Nature is a mixed bag. It is not William Paley's happy world of everything in delicate harmony and balance. It is not the widely caricatured Darwinian world of nature red in tooth and claw. Nature contains evil design, jerry-built design, and exquisite design. Science needs to come to terms with design as such and not dismiss it in the name of dysteleology.

William Dembski, Senior Fellow
The Discovery Institute
Center for the Renewal of Science and Culture